1. Field of the Invention
The present invention relates to a technique for cooling an IC card inserted in a slot of an IC card mountable device such as a portable personal computer.
2. Description of the Related Art
In a portable computer such as a notebook personal computer, it is necessary to meet both a requirement of high functionality and multiple functionality and another requirement of size reduction and weight reduction, these requirements being contrary to each other. To meet these requirements, an IC card conforming with the standard by PCMCIA (Personal Computer Memory Card International Association) or the like is removably inserted into a slot of an IC card mountable device such as a portable personal computer. Such an IC card is dedicated to each of various additional functions (e.g., extension memory, communication modem, hard disk unit), and it is fully inserted into the slot of the IC card mountable device for use by an user as required. The IC card is formed by covering a printed wiring board on which electronic components such as an LSI are mounted, with resin by resin molding to form a cardlike configuration, or by accommodating the printed wiring board in a flat boxlike metal housing.
In recent years, high integration in such an IC card has been developed to cause an increase in heating value. Further, it has also been considered to mount a CPU having a high heating value in the IC card. However, no specific measures for cooling the IC card have conventionally been made, so that there is a problem that the IC card may malfunction or fail because of a temperature rise by its heating. Accordingly, it is difficult to expect higher integration in the IC card, and electronic components having high heating values, such as an CPU, cannot be mounted in the IC card. Further, in addition to the heat from the IC card itself, the heat from any heating parts mounted in the IC card mountable device other than the IC card sometimes has an influence upon the temperature rise of the IC card, causing a similar problem.
It is therefore an object of the present invention to provide a technique for cooling an IC card with a high efficiency to allow higher integration in the IC card and allow mounting of electronic components having high heating values, such as a CPU.
In accordance with an aspect of the present invention, there is provided an IC card adapted to be removably inserted into a slot of an IC card mountable device, comprising a card housing formed like a substantially rectangular card with an inside space defined therein, the card housing having a plurality of openings through a wall of the card housing; a printed wiring board accommodated in the card housing; and a plurality of electronic components mounted on the printed wiring board.
When the IC card is inserted into the slot of the IC card mountable device, the air inside the IC card mountable device flows from the openings into the card housing, and the air inside the card housing flows out from the openings together with the heat inside the card housing, thereby cooling the electronic components. The dimension of the card housing in a direction of insertion of the IC card into the slot may be set so that the card housing has a first portion present inside the slot and a second portion projecting outward from the slot in the condition where the IC card is inserted in the slot. Further, heating components of the electronic components may be located on a portion of the printed wiring board accommodated in the second portion of the card housing. Accordingly, the heat generated from the IC card (especially, from the heating components of the electronic components) can be radiated from the second portion of the card housing to the outside of the IC card mountable device, thereby improving the cooling efficiency.
In accordance with another aspect of the present invention, there is provided an IC card cooling tray adapted to be removably inserted into a slot of an IC card mountable device in a condition where an IC card is held on the cooling tray, comprising a tray body formed like a substantially rectangular thin plate so that the IC card is kept in close contact with the tray body; and a holding member formed integrally with the tray body, for removably holding the IC card. The tray body and the holding member may be formed of a material having a high heat conductivity, such as copper.
The IC card is held by the holding member in such a condition as to be kept in close contact with the tray body, thus being integrated with the IC card cooling tray. The assembly of the IC card and the IC card cooling tray is inserted into the slot of the IC card mountable device. The heat generated from the IC card is transferred to the IC card cooling tray formed of a material having a high heat conductivity, because the IC card is kept in close contact with the tray body, thereby cooling the IC card with a high efficiency. The dimension of the tray body in a direction of insertion of the IC card tray into the slot may be set so that the tray body has a first portion present in the slot and a second portion projecting outward from the slot in the condition where the cooling tray is inserted in the slot. Accordingly, the heat transferred from the IC card to the cooling tray can be radiated from the second portion of the tray body to the outside of the IC card mountable device, thereby improving the cooling efficiency.
The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description and appended claims with reference to the attached drawings showing some preferred embodiments of the invention.